Cushion blanking die



Aug. 8, 1944. R; PETERSON CUSHION BLANKING DIE Filed Oct. 30, 1942 5 Sheets-Sheet 3 /IVVENTOE EO-SWA I. D PETERSON 1944- R. PETERSON 2,355,556

I CUSHION BLANKING' DIE Filed Oct. 50, 1942 5 Sheets-Sheet 5 /IVVENTOE EQSWALD PETEEJON Patented Aug. 8, 1944 Roswald Peterson, Minneapolis, Minn, assignor to Dayton Rogers Manufacturing 00., Minneapolis, Minn., a corporation of Minnesota Application October 30, 1942, Serial No. 463,970

14 Claims.

7 This invention relates to new and useful improvements in .cushion blanking dies, and more particularly to such dies commonly referred to by the trade as temporary blanking dies, although not necessarily.

Attempts have heretofore been made to develop blanking dies utilizing air as a means for ejecting the blanks from the die after each blanking operation, Some such devices were constructed in such a manner as to allow the blanked out pieces to fall below the die where they were subjected to a blast of air which would eject them from the press into a suitable receiving means. In other types, the blanking, die was so constructed as to allow the blanked out piece to stay in the die secured to the ram, until the ram 01'' the press had ascended upwardly into engagement with a knock-out plate supported in the die, which would push the blank out of the die. Then, as the blank would drop downwardly from the die, a blast of air would eject the blank from r the press.

Another known type of blanking die utilized a punch which was permanently attached to a metal plate having a plurality of holes therein; The punch and pad were clamped to the bolster plate of the press and allowed a plurality of stripper pins to pass freely thru a corresponding number of holes in the plate secured to the punch. The temporary blanking die was located on top of the stripper pins so as to allow the punch to enter the stripper plate nest suiiicientlv to guide the punch into the die. A cavity was provided in the underside of the die, whereby after the blank was blanked out, an air blast would sweep under the die and eject the blank from the press.

To the best of my knowledge, none of the above-mentioned methods of'ejecting blanks or stampings from punch presses have proven practical, primarily because the action of the air to eject the stampings or blanks, was not positive enough to prevent occasional jamming oi the die and punch with the work. The construction of the afore-mentioned apparatus was also such that it was difllcult to guide the work between the punch and die at high speed without interrup ion, because of the inefliciency of the means provided for temporarily bringing the work to a stop in proper-position with respect to the punch and die, each time a blank or stamping had been punched therefrom and the work advanced for the next stamping.

The novel apparatus herein vdisclosed is the result'of considerable experimental and development work in an efiort to provide an apparatus of this character which can be used for producing fiat stampings at extremely high speed, whereby the cost of producing uch stampings may be materially decreased, and with the assurance that each stamping will be accurately formed.

An object of the present invention, therefore, is to provide a cushion blanking die for punch presses, having means for positively ejecting the blank from the die into the path of a blast of air, following each punching operation, whereby such blast of air may laterally eject the blank or stamping from between the die and the ram, into a suitable receiving means.

A further object is to provide a cushion blanking die comprising a knock-out pin'or rod, preferably mounted in the die cushion, below the path of travel of the work through the press, and means being' provided for operating said knock-out pin in timed relation to the travel or the ram, whereby each time the ram moves away from the path of travel of the work, following each blanking operation, said knock-out pin is operated to eject or knock the stamping out of the die and into a position where it may readily and postively be ejected from the pres by a blast of air.

' A further object of the invention resides in the novel construction of the punch holder plate to which the blanking punch is secured, and which is provided with a plurality of apertures adapted to receive cushion stripper pins, and whereby said pins may be inserted in selected apertures in the punch holder plate in such a manner as to substantially surround the punch,

thereby to adequately support the die plate and I nest during each blanking operation of the ram.

A further object resides in the novel construction of the means for automatically stopping the work or sheet of material being fed through the machine in proper alignment with the punch and die, following each stamping operation, and which stop means is adapted to be moved out of operative engagement with the work, by relative. movement of the nest, or by any known instrumentallty, when the ram is actuated to operate the die or punch to blank a stamping from the strip of material or work.

Other objects of the invention reside in the unique arrangement and timing of the various mechanisms of the apparatus, whereby an operator may feed the work thru the press without interrupting the operation of the press for each stamping, as is now more or less common practice; in the novel construction of the knock-out rod or pin and the means for operating it in timed relation to the reciprocal movement-of the ram; in the novel construction of the punch holder plate whereby a given punch holder plate may be utilized for supporting punches of diflerent shapes and sizes, and also whereby the punch may be substantially completely surrounded by stripper pins which engage the nest adjacent to the punch, and provide an adequate support for the nest and the die secured thereto, during the stamping operation; in the specific construction of the sto means for the work, the operation of which is controlled entirely by the movement.

of the die plate and the nest, whereby each time a blank has been punched from the work or strip of metal, the stop means will automatically release the work or strip of metal, and permit it to be advanced by suitable means, not shown to the next position for punching a blank therefrom, said stop means being entirely automatic whereby it will require no attention on the part of the operator during the operation of the press; and in the provision of a cushion blanking die which may readily be embodied in a conventional ress at low cost, and which is so constructed that when a piece of work as, for example, a long strip of sheet metal from which numerous stampings may be punched, is fed into the press, the operator may depress or actuate-the usual clutch control lever or trip of the press and retain it in operative position so that the strip of sheet metal may be fed thru the press substantially without interruption, by any known intermittent strip feed, not shown.

Other objects of the invention will appear from the following description and accompanying drawings and will be pointed out in the annexed claims.

In the accompanying drawings there has been disclosed a structure designed to carry out the various objects of the invention, but it is to be understood that the invention is not confined to the exact features shown, as various changes may be made within the scope of the claims which follow.

In the drawings:

Figure 1 is a vertical sectional view of a punch press showing the invention embodied therein;

Figure 2 is a front view of the press, partially broken away, to more clearly illustrate the application of the invention thereto;

Figure 3 is a fragmentary view of the upper' portion of the press, showing the means provided for controlling the blast of air for ejecting the blanks from between the blanking die and Figure 4 is a fragmentary view substantially on the line l4 of Figure 1, showing the operative connection between the operating arm of the knock-out pin argi the crankshaft;

Figure 5 is a plan view of the cushion blanking die assembled on a smaller scale;

Fi ure 6 is an enlarged detail sectional view substantially on the line 8-5 of Figure 5;

Figure 7 is a sectional view on the line 1-1 of Figure 5, showing the stop lever in operative engagement with the work to temporarily interrupt the feeding movement thereof;

Figure 8 is a similar view showing the blanking die actuated by the ram, and also showing the stop lever moved out of operative engagement with the work to permit the work to be advanced, when the blanking die is moved out of operative engagement with the punch upon the return stroke of the ram;

Figure 9 is a view showing a blank ejected from the blanking die by the knock-out pin, and whereby it has been moved into a position to be ejected from the press by a blast of air; and

Figure 10 is a plan view of the punch holder plate, showing the bolt holes and guide holes provided therein to facilitate mounting different size punches thereon, and also for guiding the ly extending portion 6, as best shown in Figure 1. The horizontal frame portion 5 has an opening 1 therein for receiving the upper portion of the usual die cushion, generally designated by the numeral 8.

The press frame 2 is shown supported upon a suitable base, generally designated by the numeral' 9. To vary the angle'of the press frame to the vertical, the forward lower portions of the, press frame are pivoted to the base 9 by suitable pivots H, and the press frame is secured in adjusted position on the base by clamping elements l2, movable in arcuately formed slots l3 provided in the base 9.

The usual crankshaft H is shown mounted in suitable bearings l5 provided in the upper portion of the side frame members 3, and a flywheel It may be mounted for continuous rotation on the end portion I! of the crankshaft. The flywheel l6 may be driven from a suitable source of power, not shown.

As is well known in the art, the crankshaft I1 is adapted to be operatively connected to the constantly rotating flywheel l6 by aconventional one-revolution clutch mechanism, not shown in the drawings. The operation of the clutch mechanism may be controlled by the usual trip or operating lever provided for such purposes, whereby each time said trip is manuallyeoperated, the clutch will operatively connect the crankshaft to the flywheel, whereby the crankshaft is rotated one revolution. A suitable brake mechanism, generally designated by the numeral I8, is shown mounted on the opposite end portion 19 of the crankshaft, and serves to prevent overrunning of the crankshaft, each time it is released from the flywheel.

A ram 2| is mounted for reciprocal movement in vertical guides 22 provided in the side frame members 2 of the press, as best shown in Figure 2. One end of the ram is operatively connected to one end of a suitable pitman 23, as indicated at 24 in Figures 1 and 2, and the opposite end of the pitman 23 has a split bearing 25 connecting it to the crankshaft. The above-described parts of the press are well known in the art, and form no part of the present invention, except as to their association therewith.

An important feature of the present; invention resides in the construction and operation of the cushion blanking die, and, particularly in the means for electing the stampings or blanks from the die and punch, at the termination of each blanking operation of the ram.

As best shown in Figure 6, a suitable bolster therewith as a unit.

late 26 is shown supported on the horizontal frame portion of the press frame, and is secured thereto by suitable means, not shown. The bolster plate 26 has a central opening 21 therein adapted to receive a filler block 23, which is supported upon or rests on the upper end 29 of the movable frame 3| of the die cushion 6.

The die cushion, as best shown in Figures 1 and 2, comprises the movable frame portion 3|, whose upper end is engaged with the filler block 23, as previously stated. The die cushion frame 3| is shown provided at its lower end with a suitable counterbore 32 adapted to receive a suitable cushion element 33,'the upper end of which is'engaged with the bottom of the coimterbore 32.

- The opposite or lower end of the cushion element 33 is engaged with a circular plate or washer 34, adjustably supported on a sleeve 35 by a suitable adjusting wheel 36 received in threaded engagement with the lower end of the sleeve. The upper end of the sleeve 35 is secured to a member 31 seated against the upper face of an upstanding hub 38, provided on the die cushion frame 3|. as illustrated in Figure 1. l The upper end portion of the sleeve 35 is slidable in the hub 38.

The die cushion 8, as a whole, is suspended or supported from a supporting bar 39 fixedly bolted to the horizontal frame portion 5 of the press frame by suitable bolts 4|, as shown in Figure 2. To thus support the die cushion, a tubular member 42 has its upper end portion secured to the supporting bar 39 by suchmeans as screw threads 43, shown in Figures 1 and 2. The tubular member 42 is mounted within the sleeve 35, and has a suitable adjusting wheel 44 received in threaded engagement with the, lower end thereof. The upper face of the hub of the adjusting wheel 44 engages the lower terminal of the sleeve 35, whereby the sleeve 35 and washer 34 are normally restrained against relative downward movement. The sleeve 35 and washer 34 may, however, be vertically adjusted upon the tubular member 42 to properly tension the cushion element 33, by rotation of the handwheel 44, as will readily be understood by reference to Figure From the foregoing, it will be understood that the tubular member 42 is fixedly secured in the ceived in selected apertures 53, provided in the punch holder plate 45. The threaded terminals of the cap screws 52 are .received in correspondingly tapped holes provided in the punch 5|, as clearly shown in Figure 6.

Another feature of the invention resides in the unique construction of the punch holder plate 45 which, as ,clearly illustrated in Figure 10, is provided with a plurality of bolt holes 53 for selectively receiving the bolts 52. By thus providing a plurality of bolt holes 53 in the punch holder 45, punches of various sizes may be secured to the punch holder without the necessity of drilling new holes in the punch holder for different punches, or using punch holder plates with vari-' ous drillings. in the different punches 5| is determined from the bolt holes 53 provided in the punch holder plate 45. 1

By reference to Figure 10, it will be noted that the punch holder plate 45 is also provided with a plurality of spaced guide holes 54 adapted to selectively receive a plurality of cushion stripper pins 55 mounted for sliding movement in the guide holes or apertures 54. The lower ends of the stripper pins 55 are seated upon the filler block 28, and their upper ends are engaged with the usual nest and material'guide, generally designated by the numeral 56, and which also serves as a stripper plate for stripping the temporary die plate 51 from the punch 5|. The nest 56, as is well known in the art, is secured to the die plate supporting bar 39, and is therefore restrained ment on the sleeve 35, and is restrained against such movement only by the tension in the cushion element 33, which is such as to normally hold the upper horizontal portion 29 of the die cushion frame 3| against the filler block 26, which is constantly engaged with the portion 29 of the die cushion frame, and is therefore movable A punch holder plate, generally designated by the numeral 45, is removably supported upon the bolster plate 26 by suitable clamping elements 46 secured to the bolster plate 26 by cap screws 41, as shown in Figure 6. The inner end portions 46 of the clamping elements 46engage the adja-,- cent marginal edge portions of the punch holder plate 45, and the outer end portions of said clamping elements are seated upon flller blocks 49, as shown. A suitable punch 5| is secured to the punch holder plate 45 by cap screws 62 re- 51, which, in the present instance, is supported in operative relation to the punch 5| by the stripper pins 55 and the overhanging end portions 56 of the clamping elements 46, as best shown in Figure 6.

The die plate 51 has an opening 59 therein, the contour of which corresponds to the contour of the punch 5|, as is well known. The nest 56 is provided with a passageway 6| for receiving the strip material 62 from which the stampings are blanked. The passageway 6| inthe nest is so located as to accurately guide the strip material 62 between the punch 5| and the die 51, as clearly shown in Figure 6, it being understood that the die plate 51 is constantly held in engagement with the overhanging end portions 58 of the clamps 46, as a result of the cushion element 33 constantly exerting a pressure against the stripper pins 55 thru the die cushion frame 3| and the filler block 28. By reference to Figure 6, it will be noted that the over-all length of the stripper pins 55 is such that the upper face of the filler block 28 cannot engage the punch holder plate 45, and also whereby the upper portion 29 of the die cushion frame 3| cannot engage the bottom of t e bolster plate 26. Thus, the die plate 51 v is normally yieldably held against the end portions 56 of the clamps 46 by the tension in the cushion element 33. a

To retain the die plate 51 in accurate alignment with the punch 5|, the parts are so positioned thatthe punch isalways received in a guideaperture 63provided in the lower wall of the nest 56, whereby the opening 59 in the. die plate cannot become disaligned with the punch 5|, because of the nest '56 being fixedly secured to the die plate by such means as rivets 64. The die plate '51 may readily be detached frorn-the press by simply releasing the clamps 46, which also permits convenient removal of the punch holder plate from the bolster plate '26.

By providing the punch holder plate with a plurality of spaced holes 53 for receiving the The location of the tapped holes bolts 52, many different sizes of punches may be secured to the punch holder plate without the necessity of drilling new holes in the punch holder,

it being understood that the holes to be drilled exerted on the stripper plate or nest 55 around the punch, whereby the nest and temporary die plate 51 will readily respond to the stripping pressure. exerted thereon by the die cushion 8. Another important feature of the invention resides in the mechanism provided for automatically controlling the traveling or feeding movement of the strip material between the punch and die, after each blank has been punchedtherefrom. This mechanism is best shown in Figures 7, 8 and 9, and comprises a stop finger, generally designated by the numeral 55, having one end secured to a head 55 mounted for rocking movement on a block 51. The block 51 is longitudinally adjustable on a rearwardly extending bar 58 having its forward end suitably secured to the punch holder plate 45 by screws 58, whereby the stop finger and its supporting means is removable as a unit with the punch holder plate 45, as will readily be understood byreference to Figures to 9, inclusive.

A suitable stud 1| is secured to the block 51 and is slidable in an elongated opening or slot 12 provided in the supporting bar 58. A clamping bolt 13 also traverses the slot 12 and is received in a suitable aperture provided in the block 51. The bolt 13 has a flat head received in a recess 14 provided in the bottom face of the bar 58. A suitable clamping nut 15 is received in threaded engagement with the opposite end of the clamping bolt 13, and preferably. has an operating handle 15 to facilitate rotating the nut 15 to secure the block 51 in adjusted position on the supporting bar 58. The end portion 11 of the supporting bar 58 is preferably fitted into a recess provided in the adjacent edge portion of the punch holder plate 45, whereby th bottom face of the supporting bar 58 is fiushwith the bottom face of the punch holder plate 45, as will be noted by reference to Figures '1, 8 and 9.

The forward end portion 18 of the stop finger 55 is upwardly oifset, as shown in Figures '1, 8 and 9, and is provided with a detent 18 adapted to be successively received in the openings 88 provided in the strip material 52 as a result of punching the stampings therefrom.

The head 55 of the stop finger 55 is loosely supported on the adjusting block 51 by suitable spaced studs 8| and 82, secured in the block 51 and received in elongated apertures 83 provided in the head 55 of the stop finger. By thus sup porting the head 55 of the stop finger 55 upon the block 51, the head 55 is adapted for limited longitudinal movement thereon, and it is also adapted for rocking movement, as will be noted by reference to Figure 8.

The head 55 of the stop finger 55 is retained in operative position upon the adjusting block 51 by a suitable tension means, such as a pair of springs 84, shown in Figures 5 and 9. On

such spring is shown provided at each side of the head 55, and each has one end attached to the head, as shown at 85 in Figures 5 and 9. The opposite ends of the springs are attached to laterally extending pins 88 secured to the forward end of the adjusting block 51. The intermediate portions of the spring pass under pins 81 secured to the block 51, whereby the springs, in addition to constantly urging the stop finger 55 in a forward direction, or towards the punch 5|, as shown in Figure 9, also exert a downward pull on the rear end of the head 55, for reasons subsequently to be described.

The purpose of the stop finger 55 is, as hereinbefore stated, to positively arrest the forward or traveling movement of the strip material 52 at the proper time, each time it is fed forwardly following a punching operation. The operation of the stop finger 55 is controlled entirely by the action of the springs 84 and the downward movement of the nest or stripper plate 55, secured to the die plate 51.

In Figure 7, the ram 2| is shown in its normal elevated position about to descend, and the strip material 52 is shown moved forwardly into position to have a stamping punched therefrom. In this position of the strip material, it will be noted that the detent 18 of the stop finger is engaged with a wall of the opening 80, last punched in the strip 52, whereby further forward movement of the strip material is positively prevented.

When the punch 2| commences its downward movement, and engages the die plate 51, the die plate, and the nest 55 which supports and guides the strip material beneath the die plate, are simultaneously forced downwardly by the punch against the tension of the cushion element 33, as a result of the stripper pins 55 being interposed between the nest and the filler block 28, which rests upon the upper wall portion 28 of the die cushion frame 8. Such relative downward movement of the die plate and nest will cause the punch 5| to enter the opening 58 in the die plate and thus punch a stamping from the strip material 52. At the same time, the detent 18 of the stop finger 55 will be moved out of engagement with the wall of the opening 80 in the strip material 52 as a result of the nest engaging the offset portion 18 of the stop finger. Such engagement of the nest with the offset portion 18.01 the stop finger will rock the stop finger from the position shown in Figure 7 to that shown in Figure 8, thereby releasing the strip material for its next forward movement,

When the punch commences its upward movement, the die plate 51 and nest 55 will return to their normal positions, shown in Figure 7, and at the same time thesprings 84 will move the stop finger forwardly from the position shown in Figure 8 to that shown in Figure 9, whereby the detent 18 will engage the bottom face of the unpunched metal portion of the strip material 52, as clearly illustrated in Figure 9. When the detent 18 is thus engaged with the bottom surface of the strip 52, the latter may'readfly be moved forwardly to the next punching position, shown in Figure '7, in which position its forward movement will be positively arrested as a result of the detent 18 entering the last made opening 88 in the strip material 52.

From the foregoing it will be noted that the operation of the stop finger 85 is automatic, as

its operation is controlled entirely by the up and-down movement of the stripper plate or nest 58, and the traveling movement of the strip material 62 thru the press.

If the stop finger 65 should, for some reason, fail to release the strip material 62, the stop finger may be manually operated by means of a suitable operating handle 88 provided at one end of a laterally extending arm 89 secured tothe head 86 of the stop finger. The operating handle 89 is conveniently located whereby the operator may readily grasp it and operate the stop finger 65, should such an occasion arise.

Another important feature of the invention resides in means provided for ejecting the blanks or stampings 90 from between the ram and die plate at the conclusion of each stamping operation.

The means provided for thus ejecting the blanks is shown comprising a knock-out pin 9I provided at the upper end of a rod 92 which is slidably supported in the tubular member 42 of A the die cushion 8, as best shown in Figure 1. The upper end of the rod 92 traverses suitable openings provided in the upper wall 29 of the die cushion frame 8 and the filler block 28, and also passes thru aligned openings in the punch holder plate 45 and punch The knock-out pin 9| functions to knock the stamping 90 out of the opening 59 in the die plate 51, at the termination of each punching operation, as will readily be understood by reference to Figures 7, 8 and 9.

The means provided for positively operating the knock-out pin 9I is shown comprising a lever 93 having one end secured to a cross shaft or rod 94 shown mounted in depending brackets 95 secured to the press frame. The opposite end of the lever 93 has an antifriction roller 96 mounted thereon, adapted to engage a flat head 91 provided on the lower end of the knock-out rod 92. A suitable spring 98 has one end sesecured to the lever 93 and its opposite end to idler sprockets I02 and I03, as shown in Figures 1 and 4. A similar cable I04 has its lower end secured to the opposite end of the chain section IOI and its upper end to one end of a chain section I05, having a running connection with a sprocket I08. The sprocket I00 is shown mounted on a bracket I01 secured to the tie member 4 of the press frame. The chain section I05 has a threaded rod I08 secured to its oppositae end, which is received in an opening provided in an arm L09, pivoted to a bracket III secur d to the tie member 4 of the press frame, ass own in Figure 1.

A nut 'I I2 is received in threaded engagement with the adjusting screw I08 of the chain section I05, and engages a washer II3, between which and the arm I09 a suitable spring II4 is interposed. The spring II4 exerts a tension on the flexible connection between the lever 93 and the arm I09, whereby the roller 99 of the lever 93 is constantly held against the head 91 of the knock-out rod 92 by a yielding pressure.

The arm I09 is adapted to be actuated by movement of the upper end of the pitman 23, and is mounted on the arm I09 by a suitable bracket II1 having one end'suitably secured to the arm.

The roller II5 of the arm I09 is normally positioned as indicated by the dotted lines in Figure 1, in the path of the lug III; on the pitman 23.

Thus each time the crankshaft makes one revolution, the lug II6 of the pitman 23 will engage the roller H5 and oscillate the arm I09, whereby the lower lever 93 is swung upwardly against the tension of the spring 98 as a result of its connection with the arm I09, thru the cable sections 99 and I04 and the chain sections IM and I05. Such upward movement of the lever 93 will actuate the knock-out pin 9I and thereby eject the blank or stamping 90 from the die block 51, as clearly illustrated in Figure 9.

The operation of the knock-out pin 9| is so controlled and regulated that it will hold the stamping '90 against the bottom face of the ram, as shown in Figure 9, until the ram approaches the limit of its upward movement. Just before the ram reaches the limit of its upward movement, the projecting or lug IIB on the upper end of the pitman will release the roller II5, whereupon the knock-out pin will be returned to its normal inoperative position by the spring 98, shown in Figure 6. A suitable adjusting screw II8 may be provided in the arm I09 for limiting the forward movement of said arm, and also whereby the upper terminal of the knock-out pin 9| may be properly positioned with respect to the stamping 90, as shown in Figures '1 and 8. v

Another feature of the invention resides in the means provided for laterally ejecting the stampings 90 from between the ram and die plate, each time the kock-out pin 9| releases a; stamping, as when the ram approaches the limit of its upward movement or stroke.

The means provided for thus ejecting the stamping is shown comprising a pneumatic nozzle II9, mounted to project a blast of air against each stamping, at the moment that it is released by the knock-out pin 9|, as indicated in Figure 1, whereby each stamping will be quicklyand positively ejected from between the ram and the die plate, at thetermination of each stamping operation. A suitable tray or pan I20 is suitably located on the press to receive the finished Dunchings, as shown in Figure 1. The nozzle H9 is secured to the lower end of a pipe I2I, supported on the frame of the press by a suitable bracket I22, as shown in Figure 3. One end of'a flexible connection or hose I23 is secured to the upper end of the pipe I2I by a suitable fitting I20, and has its opposite or upper end connected to a. suitable control valve I24, having a pipe I25 connecting it to a source of air supply under pressure, not shown.

The valve I24 has a control plunger I26 adapted to be actuated by an arm I21 having a roller I28 engaged-by a cam I29 secured to the end portion I9 of the crank shaft I4. The cam I29 is so positioned with respect to the arm I21, that each time the ram reaches the limit of its upward movement and the knock-out'pin 9| releases a stamping 90, the valve "I24 is momentarily opened, whereby a blast of air is projected shown provided with a roller I I5 adapted to engage a lug or projection I I6 fixed to the upper end portion of the pitman 23, as clearly'illus-,

from the nozzle II9 against the stamping. thereby ejecting the stamping from between the ram and die block and delivering it into the pan I20.

The operation of the ejecting mechanism above described, including the knock-out pin 9I and the air control valve 94, is entirely automatic, and is not dependent upon the operator. This makes it possible to feed the strip material 62 thru the press at a high rate of speed and substantially without interrupting the operation of the press. In other words, the usual trip for engaging the crankshaft with the constantly rotating flywheel, may be depressed and retained in such position, whereby the crankshaft will rotate simultaneously with the fly- 'wheel with the result that a stamping is punched from the strip material 62 each revolution of the flywheel.

The above-described mechanism, as clearly illustrated in the drawings, is comparatively simple and may readily be embodied in punch presses of conventional design at little cost. In actual operation, it has been found that by the utilization of the present invention in connection with conventional punch presses, it has been possible to operate many such presses at much higher speeds than has heretofore been possible. In some instances it has been possible to increase production as much as five hundred per cent, depending upon the size of the punchings, thereby greatly reducing the cost of producing stampings in quantity production.

The mechanisms for controlling the feeding movement of the strip material 62, and for ejecting the stampings from the press, are so arranged that the press may be operated continuously while punching the stampings from each piece of strip material. In other words, all of the mechanisms of the press are so controlled and regulated that the usual clutch trip lever of the press, not shown, may be retained in operative position, whereby the crankshaft will rotate synchronously with the flywheel whereby a stamping is produced for each revolution of the flywheel, while feeding a piece of strip material thru the press.

It will be apparent to those skilled in the art that I have accomplished at least the principal objects of my invention, and it will also be apparent to those skilled in the art that the embodiments herein described may be variously changed and modified, without departing from the spirit of the invention, and that the invention is capable of uses and has advantages not herein specifically described; hence it will be appreciated that the herein disclosed embodi-- ments are illustrative only, and that my invention is not limited thereto.

I claim as my invention:

1. A punch press including a bolster plate, a ram and a die cushion, a punch holder supported on the bolster plate, a punch on the punch holder, a die plate supported over the punch, means for guiding the material to be punched between the punch and die plate, said punch holder having a plurality of stripper pin holes therein arranged in closely spaced relation over an extended zone of use thereof whereby a plurality of stripper pins may be placed in holes adjacent punch peripheries of varying sizes ,and shapes, whereby the stripping pressure exerted against the die plate to strip the die from the punch is uniformly distributed on the die around the die opening, and a knockout pin for ejecting the stamping from the die plate.

2. A punch press comprising a frame including a bolster plate, a mm. a crank shaft and a die cushion, a punch on the punch-plate, a die plate supported over the punch and having a nest secured thereto provided with a passageway for guiding the material to be pimched between the punch and die plate, said punch holder having a plurality of stripper pin holes therein arranged in closely spaced relation over an extended zone of use thereof whereby a plurality of stripper pins, may be placed in holes adjacent punch peripheries of varying sizes and shapes with their opposed ends engaging the nest and die cushion, whereby a uniform stripping pressure is exerted against the nest and die around the die opening when stripping the die from the punch, a knockout pin in the punch holder, and means made operable by rotation of the crank shaft to actuate the knockout pin to eject the stamping from the die upon the return movement of the ram.

3. A punch press comprising a frame including a bolster plate, a ram, a die cushion, a punch holder supported on the bolster plate, a punch on the punch holder, a die plate supported over the punch and having a nest secured thereto, said nest having a passageway for guiding the strip material to be punched between the punch and die plate, 'a plurality of guide holes in the punch holder, stripper pins selectively supported in said guide holes and engaging the nest and the die cushion, said stripper pins being located around the circumference of the punch in proximity to the periphery thereof, whereby a uniform stripping pressure is exterted against the nest and die when stripping the die from the punch, and a knock-out pin for ejecting the stripper pins mounted in the punch holder with their lower ends engaging the die cushion, a die plate mounted over the punch and having a nest secured thereto and resting upon the upper ends of the stripper pins, said nest having a passageway therein for guiding the strip material between the punch and die plate, a knockout pin mounted for reciprocal movement in the punch holder and normally disposed below the path of travel of the strip material fed between the punch and die plate, and means for actuating said knock-out pin to elect the stamping from the die plate, following the punching operation.

5. A punch press comprising a frame including a, bolster plate, a ram, a die cushion, a punch holder supported on the bolster plate, a punch secured to the punch holder, a plurality of stripper pins mounted in the punch holder with their lower ends engaging the die cushion, a die plate mounted over the punch and having a nest secured thereto and resting upon the upper ends of the stripper pins, said nest having a passageway therein for guiding the strip material between the punch and die plate, a knock-out pin mounted below the path of travel of the strip material fed between the punch and die plate, means for momentarily directing a blast of air between the ram and the die. during the return stroke of the ram, and means for actuating said knock-out pin to eject the stamping from the die into said blast of air, whereby said blast of air will laterally eject the stamping into a suitable receiving means.

6..A punch press comprisinga frame includ ing a bolster plate, a ram mounted over the bolster plate, a, die cushion "suspended beneath the bolster plate, a punch holder supported on the bolster plate, a punch secured to the punch holder, said punch holder having a plurality of guide apertures therein, a plurality of stripper pins selectively received in said guide apertures and arranged around the circumference of the punch, a die plate supported over the punch and having a nest secured thereto, said nest having a passageway for guiding the strip material between the punch and die plate, said stripper pins being interposed between the nest and the die cushion and yieldably supporting the die in operative relation to the punch; said die plate being mounted to be engaged by the ram, whereby it is forced into punching engagement with the punch, thereby to punch a stamping from the strip material, a knock-out pin mounted in the punch holder in alignment with the ram, -and means for actuating the knock-out pin in timed relation to the return travel of the ram, whereby said pin will cooperate with the ram'to eject the stamping from the die.

7. A punch press comprising a frame including a bolster plate, a ram mounted over the bolster plate, a die cushion suspended from the bolster plate, a punch holder supported on the bolster plate, a punch secured to the punch holder, said punch holder plate having a plurality of guide apertures therein, a plurality of stripper pins selectively received in said guide apertures, and arranged around the circumference of the punch, a die plate supported in operative relation to the punch, means for guiding the strip material between the punch and die plate, said stripper pins being interposed between the die and the die cushion and yieldably supporting the die in operative relation to the punch, said die plate being mounted to be engaged by the ram, whereby it is forced into punching engagement with-the punch, thereby to punch a stamping from the strip material, a knock-out pin mounted in the punch holder in alignment with the ram, and means ior actuating the knock-out pin in timed relation to the travel of the ram, whereby when the ram commences its return stroke, the knock-out pin will hold the blank in contact with the ram until the ram approaches the limit of its upward movement whereupon the blank is released and may be ejected into a suitable receiving means.

8. A punch press comprising a frame including a bolster plate, a ram, 9. die cushion, a punch holder supported on the bolster plate, a punch secured to the punch holder, 9. die plate, a plurality of stripper pins mounted in the punch holder and operatively associated with the die 1 cushion and die plate, means for guiding the strip material between the punch and die plate, said stripper pins yieldably supporting the die in operative relation to the punch whereby the die may be forced, into punching engagement with the punch by reciprocal movement of the ram, thereby to punch a stamping from the strip material, an air nozzle mounted adjacent to the 1 path of travel of the ram and having an operative connection with a source of air under pressure, means for controlling the flow of air from the nozzle, a knock-out pin, means for actuating the knock-out pin in timed relation to the travel of the ram, wherebywhen the ram commences its returnstroke, the knock-out pin will temporarily hold the blank in contact with the ram until the ram approaches said nomle, whereby the knock-out pin is operated to release the I stamping, and means for simultaneously actuating the air control means to cause a blastof air to be projected from the nozzle against the released stamping, thereby to laterally eject the stamping into a suitable receiving means.

9. A punch'press comprising a frame including a bolster plate and a crankshaft, a ram connected to the crankshaft, a punch holder supplate and having a connection with a source of.

air under pressure, an air control valve on said connection, a knock-out pin slidably supported in the die cushion and having its upper end adapted to pass thru an opening in the punch, but normally positioned below the path of travel of the strip material, the lower end of the knockout pin extending below the die cushion, a piv oted lever engaged with the lower end of the knock-out pin, an arm-pivoted to the upper end of the press frame and having an operative connection with said lever, cam means carried by the crankshaft for operating the arm, thereby to actuate the knock-out pin after each punching operation whereby the stamping is ejected from the die plate into alignment with the nozzle, and means for simultaneously opening the air control valve whereby a blast of air is projected from the nozzle against the stamping to deliver it into a suitable receiving means. 0. A punch press comprising a punch and a die plate, a'nest secured to the die plate and having a passageway therein for guiding the strip material between the punch and die, and a stop mechanism disposed adjacent to the punch and die comprising a detent adapted to engage the strip material to arrest its forward movement, following each punching operation, thereby to properly position the strip material with respect to the punch and die, said stop mechanism being positioned to be moved out of engagement with the strip material by downward movement of the nest during the punching operation, whereby the strip material maybe advanced until its forward movement is again interrupted by said'stop mechanism.

11. A punch press comprisingapunch and adie plate, a nest secured to the die plate and having a passageway therein for guiding the strip material between the punch and die, and a stop mechanism disposed adajacent to the punch and die. comprising an elongated member mounted for rocking and longitudinal movements, said member being adapted to successively engage.

having a passageway therein for guiding the strip material between the punch and die, an elongated member mounted for rocking and longitudinal movements, said member having an upright detent adapted to engage a wall of each blanked opening in the strip material, thereby to temporarily arrest the feeding movement of the strip material after each punching operation, and whereby the strip material will be accurately aligned with the punch and die, said stop mechanism being positioned to be engaged by the nest as said nest is moved downwardly during each punching operation, whereby the detent is automatically moved out of engagement with the strip material to permit the strip material to be advanced to the next punching position.

13. A punch press comprising a frame including a bolster plate and a ram, a punch holder supported on the bolster plate and having a punch secured thereto, a die plate supported in operative relation to the punch, means for guiding the strip material between the punch and the die plate, a stop mechanism for controlling the feeding movement of the strip material between the punch and die plate, said stop mechanism including an elongated member having a terminal detent adapted to engage a wall of each blank opening in the strip material, thereby to temporarily arrest the feeding movement of the strip material in proper position with respect to the punch and die, after each punching operation, said elongated member being adapted to be actuated by relative movement of the die during the punching operation, thereby'to temporarily release the strip material whereby the latter may be advanced for the next stamping.

14. A punch press comprising a frame including a bolster plate and a crankshaft having a ram connected thereto, a punch holder supported on the bolster plate and having a punch secured thereto, a die plate supported in operative relation to the punch, means for guiding the strip material between the punch and the die plate, a stop mechanism for controlling the feeding movement of the strip material between the punch and die plate, said stop mechanism including an elongated member having a terminal detent adapted to engage a wall of each blank opening in the strip material, thereby to temporarily arrest the feeding movement of the strip material in proper position with respect during the punching operation, thereby to temporarily release the strip material whereby the latter may be advanced for the next stamping, an air nozzle having a connection with a source of air under pressure, an air control valve, 9. knock-out pin, and means made operable by rotation of the crank shaft to first actuate the knock-out pinto eject the stamping from the die into alignment with the nozzle, after which the air control valve-is momentarily opened to cause a blast of air to be projected from the nozzle against the stamping to thereby laterally eject the stamping from the press.

ROSWALD PETERSON.

to the punch and die, after each punching operation, said elongated member being adapted to be actuated by relative movement of the die 

